Induced nitric oxide synthase is known to occur in several tissues during sepsis and inflammation. Activation of the nitric oxide pathway has both deleterious and beneficial consequences. At present, no information is available on the transcriptional regulation of human inducible nitric oxide synthase gene expression by cytokines and endotoxin. Our laboratory has recently cloned the human hepatocyte inducible nitric oxide synthase gene(Geller et al. Proc Natl Acad Sci USA 1993; 90:3491-33495). We will use this cDNA to screen a human genomic DNA library and isolate the promoter region of the human induced nitric oxide synthase gene. The promoter will be sequenced and analyzed for transcriptional factor binding sites to characterize the transcriptional regulation of this important enzyme. It is our hope that the information learned by these studies will contribute significantly to our understanding of transcriptional regulation of gene expression in sepsis and, more import antly, the regulation of induced nitric oxide synthesis in sepsis and inflammation.